HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT #4635
PERIOD
COVERED: 5am June 18 - 5am June 19, 2008 (DOY 170/0900z-171/0900z)
OBSERVATIONS
SCHEDULED
ACS/SBC
11158
HST
Imaging of UV emission in Quiescent Early-type Galaxies
We
have constructed a sample of early type galaxies at z~0.1 that have
blue
UV-optical colors, yet also show no signs of optical emission, or
extended
blue light. We have cross-correlated the SDSS catalog and the
Galaxy
Evolution Explorer Medium Imaging Survey to select a sample of
galaxies
where this UV emission is strongest. The origin of the UV
rising
flux in these galaxies continues to be debated, and the
possibility
that some fraction of these galaxies may be experiencing low
levels
of star formation cannot be excluded. There is also a possibility
that
low level AGN activity {as evidenced by a point source} is
responsible
We propose to image the UV emission using the HST/SBC and to
explore
the morphology of the UV emission relative to the optical light.
NIC1/NIC2/NIC3
8795
NICMOS
Post-SAA Calibration - CR Persistence Part 6
A
new procedure proposed to alleviate the CR-persistence problem of
NICMOS.
Dark frames will be obtained immediately upon exiting the SAA
contour
23, and every time a NICMOS exposure is scheduled within 50
minutes
of coming out of the SAA. The darks will be obtained in parallel
in
all three NICMOS Cameras. The POST-SAA darks will be non-standard
reference
files available to users with a USEAFTER date/time mark. The
keyword
'USEAFTER=date/time' will also be added to the header of each
POST-SAA
DARK frame. The keyword must be populated with the time, in
addition
to the date, because HST crosses the SAA ~8 times per day so
each
POST-SAA DARK will need to have the appropriate time specified, for
users
to identify the ones they need. Both the raw and processed images
will
be archived as POST-SAA DARKSs. Generally we expect that all NICMOS
science/calibration
observations started within 50 minutes of leaving an
SAA
will need such maps to remove the CR persistence from the science i
mages.
Each observation will need its own CRMAP, as different SAA
passages
leave different imprints on the NICMOS detectors.
NIC3/WFPC2
11192
NICMOS
Confirmation of Candidates of the Most Luminous Galaxies at z > 7
While
the deepest pencil-beam near-IR survey suggested that the Universe
was
too young to build up many luminous galaxies by z ~ 7--8 (Bouwens &
Illingworth
2006), there is also evidenc indicating the contrary. It is
now
known that some galaxies with stellar masses of M>1e10 Msun were
already
in place by z ~ 6--7, which strongly suggests that their
progenitors
should be significantly more luminous, and hence detectable
in
deep, wide-field near-IR surveys (Yan et al. 2006). As galaxies at
such
a high redshift should manifest themselves as "dropouts" from the
optical,
we have carried out a very wide-field, deep near-IR survey in
the
GOODS fields to search for z-band dropouts as candidates of galaxies
at
z > 7. In total, six promising candidates have been found in ~ 300
sq.
arcmin to J_AB ~ 24.5 mag (corresponding to restframe M(UV) < -22.5
mag
at z ~ 7). By contrast, the galaxy luminosity function (LF)
suggested
in BI06 would predict at most 3--5 galaxies over the entire
2-pi
sky at this brightness level. Here we propose to observe these
candidates
with NIC3 in F110W and F160W to further investigate their
nature.
If any of these candidates are indeed at z > 7, the result will
lead
to a completely new picture of star formation in the early
universe.
If none of our candidates are consistent with being at z > 7,
then
the depth and area of our near-IR survey (from which the candidates
are
drawn) will let us set a very stringent upper limit on the bright
end
of the galaxy LF at those redshift. As a result, our program will
still
be able to provide new clues about the processes of early galaxy
formation,
such as their dust contents and their merging time scale (Yan
et
al. 2006).
WFPC2
11202
The
Structure of Early-type Galaxies: 0.1-100 Effective Radii
The
structure, formation and evolution of early-type galaxies is still
largely
an open problem in cosmology: how does the Universe evolve from
large
linear scales dominated by dark matter to the highly non-linear
scales
of galaxies, where baryons and dark matter both play important,
interacting,
roles? To understand the complex physical processes
involved
in their formation scenario, and why they have the tight
scaling
relations that we observe today {e.g. the Fundamental Plane}, it
is
critically important not only to understand their stellar structure,
but
also their dark-matter distribution from the smallest to the largest
scales.
Over the last three years the SLACS collaboration has developed
a
toolbox to tackle these issues in a unique and encompassing way by
combining
new non-parametric strong lensing techniques, stellar
dynamics,
and most recently weak gravitational lensing, with
high-quality
Hubble Space Telescope imaging and VLT/Keck spectroscopic
data
of early-type lens systems. This allows us to break degeneracies
that
are inherent to each of these techniques separately and probe the
mass
structure of early-type galaxies from 0.1 to 100 effective radii.
The
large dynamic range to which lensing is sensitive allows us both to
probe
the clumpy substructure of these galaxies, as well as their
low-density
outer haloes. These methods have convincingly been
demonstrated,
by our team, using smaller pilot-samples of SLACS lens
systems
with HST data. In this proposal, we request observing time with
WFPC2
and NICMOS to observe 53 strong lens systems from SLACS, to obtain
complete
multi-color imaging for each system. This would bring the total
number
of SLACS lens systems to 87 with completed HST imaging and
effectively
doubles the known number of galaxy-scale strong lenses. The
deep
HST images enable us to fully exploit our new techniques, beat down
low-number
statistics, and probe the structure and evolution of
early-type
galaxies, not only with a uniform data-set an order of
magnitude
larger than what is available now, but also with a fully
coherent
and self-consistent methodological approach!
WFPC2
11218
Snapshot
Survey for Planetary Nebulae in Globular Clusters of the Local
Group
Planetary
nebulae {PNe} in globular clusters {GCs} raise a number of
interesting
issues related to stellar and galactic evolution. The number
of PNe
known in Milky Way GCs, 4, is surprisingly low if one assumes
that
all stars pass through a PN stage. However, it is likely that the
remnants
of stars now evolving in Galactic GCs leave the AGB so slowly
that
any ejected nebula dissipates long before the star becomes hot
enough
to ionize it. Thus there should not be ANY PNe in Milky Way
GCs--but
there are four! It has been suggested that these PNe are the
result
of mergers of binary stars within GCs, i.e., that they are
descendants
of blue stragglers. The frequency of occurrence of PNe in
external
galaxies poses more questions, because it shows a range of
almost
an order of magnitude. I propose a Snapshot survey aimed at
discovering
PNe in the GC systems of Local Group galaxies more distant
than
the Magellanic Clouds. These clusters, some of which may be much
younger
than their counterparts in the Milky Way, might contain many
more
PNe than those of our own galaxy. I will use the standard technique
of
emission-line and continuum imaging, which easily discloses PNe.
WFPC2/NIC3/ACS/SBC
11144
Building
on the Significant NICMOS Investment in GOODS: A Bright,
Wide-Area
Search for z>=7 Galaxies
One
of the most exciting frontiers in observational cosmology has been
to
trace the buildup and evolution of galaxies from very early times.
While
hierarchical theory teaches us that the star formation rate in
galaxies
likely starts out small and builds up gradually, only recently
has
it been possible to see evidence for this observationally through
the
evolution of the LF from z~6 to z~3. Establishing that this build up
occurs
from even earlier times {z~7-8} has been difficult, however, due
to
the small size of current high-redshift z~7-8 samples -- now
numbering
in the range of ~4-10 sources. Expanding the size of these
samples
is absolutely essential, if we are to push current studies of
galaxy
buildup back to even earlier times. Fortunately, we should soon
be
able to do so, thanks to ~50 arcmin**2 of deep {26.9 AB mag at 5
sigma}
NICMOS 1.6 micron data that will be available over the two ACS
GOODS
fields as a result of one recent 180- orbit ACS backup program and
a
smaller program. These data will nearly triple the deep near-IR
imaging
currently available and represent a significant resource for
finding
and characterizing the brightest high-redshift sources -- since
high-redshift
candidates can be easily identified in these data from
their
red z-H colours. Unfortunately, the red z-H colours of these
candidates
are not sufficient to determine that these sources are at
z>=7,
and it is important also to have deep photometry at 1.1 microns.
To
obtain this crucial information, we propose to follow up each of
these
z-H dropouts with NICMOS at 1.1 microns to determine which are at
high
redshift and thus significantly expand our sample of luminous, z>=7
galaxies.
Since preliminary studies indicate that these candidates occur
in
only 30% of the NIC3 fields, our follow-up strategy is ~3 times as
efficient
as without this preselection and 9 times as efficient as a
search
in a field with no pre-existing data. In total, we expect to
identify
~8 luminous z-dropouts and possibly ~2 z~10 J-dropouts as a
result
of this program, more than tripling the number currently known.
The
increased sample sizes are important if we are to solidify current
conclusions
about galaxy buildup and the evolution of the LF from z~8.
In
addition to the high redshift science, these deep 1.1 micron data
would
have significant value for many diverse endeavors, including {1}
improving
our constraints on the stellar mass density at z~7-10 and {2}
doubling
the number of galaxies at z~6 for which we can estimate dust
obscuration.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of potential
non-nominal performance that will be investigated.)
HSTARS:
11345
- GSAcq (2,1,1) failed to RGA Hold
At 170/13:14:11, GSAcq (2,1,1) scheduled from 13:10:21 - 13:17:38
failed
to RGA Hold. QF2STOPF flag was received on FGS 2. No other 486 ESB
messages were received. OBAD #1: V1 505.01, V2 -959.57, V3
-297.10, RSS
1124.32 arc seconds. OBAD #2: V1 -3.18, V2 1.03, V3 1.36, RSS 3.61
arc
seconds OBAD MAP: GV1 1417.46, V2 1982.64, V3 -926.74, RSS 2607.47
arc
seconds
Possible observations affected: WFPC Proposal #11202, Observation
#84-85
At 170/14:48:48, REAcq (2,1,1) scheduled from 14:45:38 - 14:52:55
failed
to RGA Hold. QF2STOPF flag was received on FGS 2. No other 486 ESB
messages were received. OBAD #1: V1 1406.32, V2 1980.32, V3
-926.51, RSS
2599.55 arc seconds OBAD #2: V1 1.38, V2 7.62, V3 5.25, RSS 9.35
arc
seconds OBAD MAP: V1 1854.26, V2 2428.33, V3 -1349.62, RSS 3340.14
arc
seconds
Possible observations affected: WFPC Proposal #11202, Observation
#86-87
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
04
03
FGS
REacq
11
10
OBAD
with Maneuver 28
28
SIGNIFICANT
EVENTS: (None)